Dispensers for liquids having relatively high viscosities, such as soaps, shampoos, tomato ketchup, mayonnaise or the like, normally take the form of a semi-rigid plastic container having an openable closure cap or a reciprocal dispensing valve mounted thereon. Conventional dispensers of this type are relatively expensive to manufacture, prone to malfunction and normally do not insure that a pre-measured charge of the liquid will be dispensed therefrom.
Other types of conventional dispensers include thin-walled plastic pouches that are heat sealed to retain a liquid product therein. A corner of the pouch is either ripped open to dispense the product or a closure plug is used for this purpose. Further, U.S. Pat. Nos. 3,009,498; 3,184,121; and 3,815,794 and Canadian Patent No. 735,289 disclose pouches or bags which provide various types of closures to seal the bags after product has been dispensed therefrom. Bags of this type are prone to leakage and require mechanical manipulation or other extraneous forces to open and close the valves thereof.